One wellness trend attracting attention concerns the vagus nerve, an 'information highway' that tells your organs how to rest. Whether through cold water plunges or external devices, stimulating the nerve to help regulate the body and potentially feel calmer is growing in popularity.
But what are the symptoms of vagus nerve dysregulation? Let's examine what 'dysregulation' actually means in practice, and explore how vagus nerve stimulation devices such as Nurosym claim it can help regulate your nervous system.
What is the vagus nerve?
The vagus - Latin for 'wandering' - nerve is a long, winding and highly branched nerve, which connects our brains to our organs. It's part of the autonomic nervous system, which controls functions we don't think about, such as breathing, heart rate and digestion.
The autonomic system as a whole is split into two: the sympathetic nervous system and the parasympathetic nervous system. The former triggers our 'fight or flight' stress response, while the latter uses the vagus nerve to apply the brakes.
What does a regulated vagus nerve look like?
There isn't a single test to determine whether your vagus nerve is regulating your nervous system. Instead clinicians may assess functions of your vagus nerve and the wider autonomic nervous system.
Heart-rate variability (HRV) measures the variation in time between heartbeats, with certain results providing information on parasympathetic nervous system activity involving the vagus nerve. Doctors can also investigate autonomic function by measuring heart-rate and blood pressure responses to controlled deep breathing techniques such as the Valsalva manoeuvre.
While evidence that an activity temporarily changes parasympathetic activity isn't the same as proof that it 'repairs' or 'resets' a dysfunctional vagus nerve, there are physical methods that affect the nerve:
- Slow breathing: A review of 223 studies found that voluntary slow breathing can increase HRV measurements associated with vagal activity, suggesting that it shifts the body towards greater parasympathetic activity.
- Cold-water immersion: There is less conclusive evidence here, but studies have shown changes in HRV after cold-water immersion that indicate increased parasympathetic activity. However more research is needed to understand whether this is just a physiological response to cold water, as opposed to one that benefits the vagus nerve.
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What happens when your vagus nerve is dysregulated?
Vagus nerve dysfunction isn't itself a diagnostic label in medicine, but there are medically recognised conditions that directly affect the vagus nerve.
These include causes such as:
- Physical damage: Direct injury to the nerve from surgery, trauma or physical compression.
- Vagal neuropathy: Nerve damage caused by disease, such as diabetes, infections or inflammatory conditions.
- Autonomic disorders: Conditions that affect the autonomic nervous system, such as vasovagal syncope.
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The term vagus nerve 'dysfunction' or 'dysregulation' is used in wellness circles and on social media. Effects on the body that might be associated with 'dysregulation' would typically be anxiety, stress, everyday fatigue or mild bloating.
What is a vagus nerve stimulator?
There are many manual ways to stimulate the vagus nerve, such as cold water immersion and slow breathing, although their efficacy can vary depending on timing, technique, intensity and the person's physiological state.
Implantable devices designed to stimulate the vagus nerve have also been in use for many years. In the late 19th century, American neurologist Dr James Corning created the first fork-like instrument intended to compress and electrically stimulate the carotid sheath and vagus nerve to treat epilepsy.
In 1988, the world's first VNS surgery was performed as an intervention for epilepsy, and in 1997, the Food and Drug Administration (FDA) approved the first implantable VNS device for such treatments. Since then, invasive devices have also been approved to treat depression and to help with stroke rehabilitation.
With the rise of 'neurowellness', at-home vagus nerve stimulators are becoming more and more prevalent. Some brands claim their devices use low-level Bluetooth technology to stimulate the nerve, while others are designed as wearable neck bands, where conductive gel must be applied as a means to deliver electrical stimulation along the neck's vagal pathway.
So, how does Nurosym work?
Worn on the ear, Nurosym stimulates the auricular branch of the vagus nerve by delivering gentle, targeted electrical impulses. This technology is known as 'auricular vagal neuromodulation therapy' and is designed to increase parasympathetic activity.
Nurosym recommends using the device for up to 60 minutes a day. It can also be worn during low-intensity tasks like walking, reading or lounging before bed.
